Recently, accidents of large ships (particularly oil tankers) at sea are becoming more frequent and spillage of oils raises alarming concern for the natural environment. Consequently, the oil spills drift toward the coasts, killing various natural wild life at sea, incurring enormous property loss.
Further, when removing the oil spills, chemicals are frequently used. As a result, the oil spills are only emulsified or are made to sink to the sea bottom, so that only the visible oil spills are removed, and no attempt has been made for the complete removal.
In order to overcome this disadvantage, Korean Utility Model Publication No. 82-1602 was proposed. In this proposal, a spiral rotor which has a spiral form side view and freely rotatable is installed on a frame in the longitudinal direction, and a driving means is installed for driving the spiral rotor, with its opening directed forward. Further, rotary vanes are installed on the frame, with the lower portion of the vane submerged into the sea water. In order to drive the rotary vanes, a driving gear is meshed with an annular rack.
However, in this apparatus, a drum with a plurality of brushes attached thereon is installed at an upstream of the spiral rotor. Further, a scrubbing roller removes the oils adhered to the brushes. However, the drum cannot be made to revolve fast due to the viscosity of the oils. As a result, the oils cannot be removed in a speedy manner. Further, there is no means for handling the water adhered to the oil, thus increasing the recovered amount (mixture of water and oil), making it necessary to have a large storage tank. As a result, the amount of actual recovered in the storage tank is relatively small.
In an attempt to overcome this disadvantage, an oil recovering ship was proposed by the present applicant under Korean Patent Application No. 95-32192. This oil recovering ship comprises: a hull having a plurality of partitioned tanks, each having floating force; an oil introducing means installed on the front part of the hull, for introducing the oil from the sea into the ship; and an oil drawing means installed on the tail part of the hull, for drawing the introduced oil.
This oil recovering ship further comprises: an oil separating/extracting means installed at the rear of the oil drawing means, for separating/extracting/recovering the drawn oil; and an adjusting means for adjusting the height of the oil drawing means and the oil separating/extracting means.
The oil drawing means consists of a water wheel having a plurality of blades, being forcibly rotatable.
However, this oil recovering ship is only capable of simply carrying out the recovering task, and therefore, a towboat is required to pull the ship to the site of an oil spill. Therefore, in an emergency, the oil recovering ship cannot be mobilized in a speedy manner.